I have the same problem. I have done everything from step 1 to 4 but I don know how to do step 5

5. delete the oald8 user preference directory ~/Library/Preferences/oald8 . Please note that '~' represents your home directory, and that this step may need performing for each user who has used the dictionary

Where can I find the oald8 user preference directory ~/Library/Preferences/oald8??